1. Field of the Invention
The preset invention relates to an electron emitter and a light emission element for outputting secondary electrons emitted from an emitter element.
2. Description of the Related Art
In recent years, electron emitters having a cathode electrode and an anode electrode have been used in various applications such as field emission displays (FEDs) and backlight units. In an FED, a plurality of electron emitters are arranged in a two-dimensional array, and a plurality of phosphors are positioned at predetermined intervals in association with the respective electron emitters.
Conventional electron emitters are disclosed in Japanese laid-open patent publication No. 1-311533, Japanese laid-open patent publication No. 7-147131, Japanese laid-open patent publication No. 2000-285801, Japanese patent publication No. 46-20944, and Japanese patent publication No. 44-26125, for example. It has been considered to make an emitter element of a dielectric material. Various theories about the emission of electrons from a dielectric material have been presented in the documents: Yasuoka and Ishii, “Pulsed electron source using a ferroelectric cathode”, J. Appl. Phys., Vol. 68, No. 5, p. 546-550 (1999), V. F. Puchkarev, G. A. Mesyats, “On the mechanism of emission from the ferroelectric ceramic cathode”, J. Appl. Phys., Vol. 78, No. 9, 1 Nov. 1995, p. 5633-5637, and H. Riege, “Electron emission from ferroelectrics—a review”, Nucl. Instr. and Meth. A340, p. 80-89 (1994).
However, in conventional electron emitters, the electron emission is not performed stably, and the number of emitted electrons is merely tens of thousands. Therefore, the conventional example of the electron emitters are not suitable for practical use. Advantages of an electron emitter having an emitter element have not been achieved.